In a semiconductor device such as, for example, a flash memory or a logic circuit, a device is formed on or in a semiconductor substrate, and an interlayer insulating film is formed to cover the device. In addition, a wiring layer is formed on the interlayer insulating film, and a contact is formed through the interlayer insulating film to electrically connect the wiring layer and certain device regions, such as source and drain regions of the devices, which are on or in the semiconductor substrate. The contact may be created by forming a hole in the interlayer insulating film which extends from a location on or in one side of the interlayer insulating film where a line, for example a bit line, is later formed, and lining the walls of the hole with a metal such as titanium (Ti), covering the titanium layer with a barrier metal film such as titanium nitride (TiN), and filling the hole with a main contact material such as tungsten. The underlying metal layer (e.g., titanium) is reacted with the silicon of the semiconductor at the base of the hole to form a contact silicide layer. However, when the metal of the contact reacts with the semiconductor substrate, during formation of a contact silicide at the interface of a contact extending through a first level insulator and the semiconductor substrate, if the amount of metal being reacted is large, excess silicon is required to complete the silicidation reaction, and a gap can be generated between the silicide layer and the semiconductor substrate where silicon has been drawn out of the substrate for the silicidation reaction with the titanium or other metal.